Characterisation of Strength Behaviour of Aluminium Foam Sandwiches Under Static Load

Cellular metals, particularly aluminium foams, are increasingly used in automotive, railcar and aircraft industries due to their advantages such as low density, comparatively high stiffness, noise damping or non-flammability. From this point of view a new powder-compact forming and foaming technique has been developed to manufacture 3D-aluminium foam sandwich (AFS) parts for components of railcars without glued joint between the foamed core layer and both cover sheets. Three different stages of foam expansion have been analysed to describe the material properties. We have characterised samples made of plane AFS panels by compression, bending and shear tests. The shear strain is optically measured by digital image correlation to estimate the shear modulus of foamed sandwiches. Furthermore, these experimentally determined values and curves are the basis for the verification and optimisation of finite element models by design of experiments. As a result of this work, recommendations could be derived for improving technological parameters.